1. Field of the Invention
The invention relates to a drawing gripper for a rapier loom fitted with means to receive and to position a filling yarn kept in readiness and resting on a deflection guide.
2. Related Art
In rapier looms, a filling yarn is conventionally made to pass through the shed using a drawing gripper and a receiving gripper. The drawing gripper receives a filling at the intake side of the shed, this filling being kept in readiness by a yarn feeder. When the drawing gripper is being introduced into the shed, the filling is received and positioned inside this drawing gripper and clamped by a clamp. At the approximate middle of the shed, the filling is transferred to a receiving gripper, then clamped by a receiving-gripper clamp and moved by the receiving gripper to the other side of the shed. Meantime the empty drawing gripper returns to its initial position in front of the shed's intake side.
It is furthermore known with respect to rapier looms to move a filling by means of a single drawing gripper through the entire shed. In this case the drawing gripper receiving the filling at the shed's intake side moves toward the opposite shed side where the filling then is released to a receiving hook or the like.
It is known from the U.S. Pat. No. 4,653,544 to make the feeder deposit the filling on a deflecting means in such manner that this filling is kept in a defined position whereat it can be reliably picked up by the drawing gripper when latter is moving toward the shed.
It is known from the European patent document 0 509 255 A1 to fit a drawing gripper (starting at its tip) with a guide surface leading to a transverse slot into which the filling to be received drops. Once the filling has been dropped into this slot, it is no longer able to slip out of it. However only those fillings may be used in weaving that shall easily slip through the slot, so that thick fillings or reinforced fillings cannot be woven at all or only with difficulty. This design has another drawback in that the filling to be received loses all its tension when dropped into the slot and then will remain wholly slack. If the filling positioned inside the drawing gripper is subsequently tensioned by the motion of the drawing gripper, then the load will be applied abruptly. The danger of filling rupture is enhanced thereby.
It is furthermore known from the European patent document 0 441 099 A1 to use a substantially U-shaped plate as the drawing gripper. The crossbar of this U-shaped plate acts as a slide surface for the warp yarns of a lower shed. The leg facing the fabric edge forms a guide surface for the filling to be received and directly guides the filling to a clamp entered by said filling. The other leg also comprises a guide surface and a clearance acting as a positioning device. This design entails the risk that the guide surface of the crossbar facing the fabric edge shall catch a warp moving slightly off-path and shall feed it to the gripper clamp. Warp rupture then inevitably results.
The objective of the invention is to so design a drawing gripper of the above-mentioned kind such that a filling kept in readiness shall be reliably seized and the danger of gripping a warp is substantially reduced.